Timing unit for switches



' E, w. RICKMEYER TIMING UNIT FOR SWITCHES Filed Apr-'118, 1944 K Feb. 1o, 194s.

. .lm/ENTOR. Ernsf W. Rikmeyer l 'Patented Feb. 10. 1948 f yover the iixed orifice.

fluid, such as mercury,

-pressure-from one side to the other of the restriction wafer to control an electrical circuit, the construction 'being such that the wafer can reference being had to the Ernst Walter Riokmeyer'. Elmhurst, Ill.. assigner to Jeierson Electric Company, Bellwood, Ill.,

a corporatlon'of Illinois ,Y application April s, 1944, serial No. 530,124

3 Claim. (01.*200-80) The present invention relates to switches and more particularly to centrifugal ,switches .whereingswherein a preferred form of the invention in a conducting iluid- (mercury) is moved by centrifugal vforce to control ,the flow of, current ina l circuit. In such devices the conducting'fluid is coniined. in a, shell which may serve as one terminal contact. The other terminal contact-may 4 comprise a contact member that opens into the shell at one end thereof and is insulatedfrom "theshell I I The switch functions to time the circuit change in response to the centrifugal force set up in the shell by the' rotation of the carrier for the shell. I TheI timing is accomplished by utilizing a restricted passage or a. plurality of restricted fpassageslthroughwhich the conducting iluid must flow under the'pressure developed by the centrifugal force.

In my application. Serial No. 530,123, led

' April 8, :1944, I haveA disclosed a switch of the general character to whichthis inventicnrapplies. `According 'to the present invention however I provide a novel construction whereby a restricted passage is provided in a. separate wafer that can be' made and testedbefore it is placed within the tubular shell of the switch.

is shown. It is tobe understood however that the drawings and description are illustrative only and are not to be taken asy limiting the invention except insofar as it is limited by the claims.

In the drawings:v Fig. 1 is a plan view of'a. rotating or spinning device wherein a circuit controlling switch vof the ,type embodying by invention is mounted;

Fig. 2 is a longitudinal sectional view through a switch embodyingmy invention; l

Fig. 3 is a view like'Fig. 2 showing a slightly modiied construction embodying my invention;

Fig. 4 is a sectional view taken on vthe li'ne 4-5 ofFig. 2; and l Fig. 5 is a plan view of the' device shown in Fig. 2. l Referring now in detail to the drawings, I show in Fig. 1 a rotating element Il) which may be mounted upon any suitable means such as a motor shaft and causedto rotate at` high speed.

The member I0 is shown with a pocket I I therein.. which pocket is adapted to seat a switch element I2. The switch element I2 is shown in It 'is the purpose of. this invention to provide a restrictlon'wafer wherein a member containin g an opening of a denite cross section is se- -curely bound up with a layer of porous material i l covering the opening.

It isV also a purpose of my invention to provide in a switch of the character described a restriction wafer wherein a cup-shaped mounting member has sealed therein the necessary parts to provide an orice of iixed cross section with -a covering of porous material, the cup-shaped member having its open end turned in so as to permanently bindthe porousmaterial in place yIt is also. a purpose of my invention to provide a novel switch construction wherein -a restriction wafer is interposed in the path of a conducting that is transferred by be preformed, pretested the switch bodywithout the capacity of the wafer to pass a, given amount and then mounted in of mercuryin a given time under a given pres- Sure,

Other detailed objects and advantages ci the invention will appear as the description proceeds,

in any way affecting.

accompanying drawlongitudinal 'section in Fig. 2 of the drawings. It comprises a shell indicated generally by .the numeral I3. This shell is constructed of4 any suitable conductingmetal since it is adapted t0 form one terminal of. the switch. Ofcourse, where it is desired to have the shell constructed of insulating material a separate terminal would have to be provided. Normally for the shell I3 I utilize a deep drawingsteel and form the shell into thetubular shape. One vend I4 of the shell is restricted in dianter toY provide a shoulder at I5 against which a restriction wafer indiv cated generally by the numeral I6 rests. The

wafer ispressed against the shoulder I5 by rolling the body of the shell inwardly to provide a reduced portion I1. Likewise at the open end of the shell I` mount a central contact assembly I8 by securing an insulating washer I9 into the open end of the shell against a shoulder 20 provided by the rolling operation. The open end of the shell is spun over as' indicated at 2| to seal the washer I9 in place'. The

contact assembly I8 comprises a, center contact' member 22 which may be of any suitable conducting material such as steel, stainless steel, copper or the like. It is secured to the insulating washer I9 by passing it through this washer and a supporting washer 23 and then'through a.l

terminal element-24, the end of the center ccntact being spun over as indicated at 25 to secure the parts together. 4

The restriction wafer IB forms a partition dividing the shell into a chamber 26 about the contact 22 and a receiving chamber 21. It is important in devices of this character that the restriction wafers be made with such accuracy and care that the timing of the switch under a given pressure tending to force a conducting fluid such as mercury from the chamber 26 to the chamber 21 or vice versa may be depended upon. It is therefore quite important that the restriction wafer be capable of testing before it is placed inthe switch assembly. My invention concerns itself with a novel construction where- I5 and upwardlyl along-l the larger portion of the shell above the shoulder.

by the restriction wafer can be made and tested before it is plac-ed in a switch assembly, and can be placed in the switch assembly and sealed so that possibility of leakage about the wafer between the two chambers and the switch can be avoided.

The restriction wafer I6 is made up of a cup 28 having an opening 29 of predetermined cross sectionl in the bottom thereof. The cup 28 preferably is constructed of steel. In the bottom of the cup I place a layer 30 of porous material. This layer isa composite layer made up of fibrous materials. For example, there is a bottom layer 3| of linen, then an intermediate thick layer 32 of paper pulp, such as blotting paper, the fibers of which are relatively long so'that the'ber length exceedsthe diameter of the opening 29. On top of the layer 32 another layer 33 of a suitable fabric such as linen is provided. The fabric layers 3| and 33 are to hold the fibrous mate- Referring now' to the construction shown in Fig. a, m uns cpnscructicn the device is slightly modiiied in order to obtainsl more accurate con--l trol of the distance between the center contact 22 and the restriction wafer opening, In this form of device the shell I3' has a reduced end I4' providing a shoulder atI5' precisely as inthe rst form of the invention. However, a different restriction wafer 381s employed. Fundamentally the wafer is of the same general construction but rial is interposed in the bottom of the cup 39 and clamped in place by the disk 4I the end of the cup 39 being rolled inward as indicated at 44 to clamp the parts together. The thickness of the l wall of the cup-being known. it is then. a deflnite distance from the outer surface of the cup to the porous material 43 where the restricted rial or pulp in place although of -course they do effect a certain amount of restriction too and they are composed of fibers of such length as to bridge the opening 29. In o'rder to securethe layer 30 o f porous material in the bottombf the cup 28 I provide an annular clamping member 34 inthe form of a flat disk having a central aperture 35 slightly larger than the aperture 29 and axially aligned therewith- I then turn the free edge 36 ofthe cup28 inwardly and roll it down over the annular clamp 34 so as to press the parts together and make the complete unit which I have termed hereinbefore the restriction wafer. This unit can be tested after it is made l and before it is placed within the shell I3. Furthe porous material 30 The parts of the restriction Wafer .I6 obviously are of such nature that they can be made individually, then assembled in high speed production with no diiiiculty, and the individual wafers can be subjected to the necessary tests to determine the rate of ow of mercury through them-before going to the trouble of assembling them in the shell I3.

I have already described how the wafer I 6 is placed within the shell against the shoulder I5 and then permanently secured against this shoulder by rolling the portion I1 of the shell inwardly. This howeveris not sulcient assurance against leakage of the mercury between the chambers 26 and 21 `around the wafer I6. Under the extreme pressures developed at high speed rotation of the shell in the member Ill the mer-- passage begins. In order to accurately space ,the contact element 22 with respect'to the restricted passage I provide a spacing sleeve 45 insidel the shell I3' and seat the washer I9 of the contact assembly on this spacing ring. The wall thickness of the spacing ring can be varied to give the desired volume in the 'chamber 26.

The restriction-wafer '38 is welded'after beingv placed within the shell I3' but in this instance it is a little more easy to get at the welding be-' cause thewelding can be done before inserting the sleeve 45, and there is no danger of subsequently damaging the joint betwen the wafer and the shell as there would be if the welding was done first in the form'shown in'Fig. 2 and the rolling of the partr I1 was done later. The fact that the'wafer cup 39 is turned so that its open end-faces the chamber 21' gives a smooth seat for the spacing sleeve 45 regardless of the thickness of the sleeve.-

It is believed to be evident from the foregoin description and the drawings that I have provided a novel restriction wafer construction to'- gether with means for mounting the same in a shell that materially improves the production of the device. The prime advantage lies in the fact that the preformed restriction wafers can be l wafer itself. Also in the form of the invention shown in Fig. 3 of the drawingsthe preformed wafer is rounded for seating against the shoulder I5'. The hat face of the wafer provides with the sleeve 45 an accurate control of the distance from the face of the center contact 22 to the restricted passage regardless of variation in shell length.

. From the 'foregoing description it is believed that the nature and advantages 0f my invention will be readily apparent'to those skilled in this art.

Having thus described my invention, what I claim as new and desire to secure by Letters Pat.. ent is:

V1. In a device of the character described, a tubular metal shell having an annular shoulder intermediate its ends, a. restriction wafer com prising a shallow. ilat bottomed metal cup member provided with an opening the bottom-said v aisance l cup member restingon said shoulder and welded,

liquid tight, to the shoulder, a layer of porous material in the bottom of said cup covering said opening, means including an inturned lip at the open end of the cup holding the layer of 'porous material in place, the cup member serving to divide the shell intotwo chambers, an electrical contact disposed in one of the chambers and Ainercury disposed in the shell.

2. In a device of the character described, a

:tubular metalshell having an annular shoulder intermediate its ends, a restriction wafer comprising a shallow, fiat bottomed metal cup member provided with an opening in the bottom, said cup member resting on said shoulder and welded, liquid tight, to the shoulder, la layer of porous material in the bottom of said cup covering said opening, an annular clamp ilxed in said cup and Y holding the outer portion of the porous-material against the bottom oi the cup but leaving the porous material over said opening uncovered, the open end of said cup being turned in to secure said clamp, the cup member serving to divide the shell into two chambers. an electrical contact, disposed in one of the chambers and mercury disposed in the shell.

3. In a device o f the character described, a tubular metal shall having an annular shoulder intermediate its ends. a restriction wafer compx'lsing a shallow, flat bottomed metal cup member provided with an opening in the bottom, said cup member resting on said shoulder and welded, liquid tight, to the shoulder, a layer of porous I material in the bottom of said cup covering said opening, an annular clamp fixed in 'said cup and holding the outer portion of the porous material against the bottom of the cup, the aperture in said annular clamp being centered with respect tosaid opening but of a. different size, the cup member' serving to divide the shell into two chambers, an electrical'contact disposed in one of thechambers and mercury disposed inthe shell.

ERNST WALTER RICKMEYER.

REFERENCES CITED .The following references are of -record in the 20 flle of this patent:

UNITED STATES 'PATENTS Number Name Date 1,144,040 Keller, June 22, 1915, 1,457,059 Fregonara May 29, 1923 1,937,507 Bijur...- Dec. 5. 1933 2,005,476 Schmitt June 18, 1935 2,088,703

Hubbard et al. Aug. 3, 1937 

